This invention relates to a regulating device for electric timepieces having electro-mechanical transducers, and in particular, to electric watches incorporating such transducers. In such timepieces, a step motor is provided driven by a signal supplied by an oscillating driving circuit which may include a crystal vibrator. A second hand is incrementally driven at one second intervals by the rotor of the transducer, which rotor is provided with alternately magnetized north and south poles and is positioned between a pair of stators. By changing the magnetic polarity produced in the stators in response to the pulse signal produced by the driving circuit, magnetic repulsion and attraction between the rotor and stator is produced and the rotor is incrementally driven once each second.
Generally, this type of timepiece is provided with a reset circuit and a regulating lever. The reset circuit has two functions, namely to cut off the flow of driving current to the coil of the electro-mechanical transducer when the reset switch is turned on, and to apply a predetermined positive or negative first driving pulse to the coil when the reset switch is turned off. The regulating lever also serves two functions. Thus, by cooperation with a regulating cam, it determines the position of the magnetic poles of the rotor relative to the stator in order that the pulse of the rotor may be arranged favorably for the operation of the rotor in view of the magnetic polarity produced in the stator by the first driving pulse produced when the reset circuit is operated. Further, the regulating lever stops the rotor so that the hour and minute hands may be manually adjusted and reset without disturbing the position of the rotor through the operation of a friction clutch arrangement between the hour and minute hands and the rotor.
Quartz crystal timepieces are highly accurate, and even a compact-size quartz crystal watch can be adjusted to a daily rate of about .+-. 0.2 second. However, over a period of tens of days, the error will be accumulated and may become large. In such instances, it will be necessary to adjust the time indication. However, the prior art regulating devices have themselves introduced errors into the time keeping due to the locking of the mechanical time indication arrangement by the regulating lever at the time of the application of the first driving pulse to the coil of the transducer.